When you have a potion on, when you move the mouse off the object list on any tab. The the box telling you witch potion you have on will turn grey. Also when you move you mouse on you hotbar when its empty or any empty slot the tab name is black, but when you slide you mouse over a square with a object in it the name of the tab is white.
MC-35835
Potion Glitch
Resolved
Duplicate
1
Katie Morton
(Unassigned)
Unconfirmed
Minecraft 13w42a
Retrieved
Creative or Survival?
Confirmed with creative but only happens when there are enchanted items in that creative tab. Try investigating when it happens according to where your mous is, and which Items (especially enchanted items) are visible.
Is probably related to MC-35810 and MC-35617.